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Buddabing's LED controller

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Trimoor:
We should include something on how to take focused pictures in the FAQ...But otherwise it looks good.

How are you controlling the LEDs?  Is it just a multiplexor and latch, or a microcontroller too?  If it's a microcontroller, you might want to use the serial port for ease of programming.

Am I right in guessing the 555 circuit in the lower right corner is left over from another project?

cholin:

--- Quote ---and two, to light up LEDs around each of the eight cardinal directions around a joystick, depending on which directions are active on the joystick.[/quote/

That was one of my ideas, although I was only going to use 4 directions.  If anything happens with this board (for a CHEAP price), I may save myself a ton of wiring!  Im sure Trimoor remembers this idea beause he practically made the circuit :)  Hope it's cheaper than the ArcaLux :P
--- End quote ---

Buddabing:

--- Quote from: Trimoor on April 10, 2005, 04:39:38 pm ---We should include something on how to take focused pictures in the FAQ...But otherwise it looks good.

How are you controlling the LEDs?  Is it just a multiplexor and latch, or a microcontroller too?  If it's a microcontroller, you might want to use the serial port for ease of programming.

Am I right in guessing the 555 circuit in the lower right corner is left over from another project?

--- End quote ---

The larger IC is a "constant-current LED display driver" chip, the medium sized one is a standard 74LS05, and the small one, you are correct, is a standard 555 oscillator that is not part of the circuit.

The driver chip runs on an I2C interface. The inverters are part of a circuit which makes the parallel port inputs I2C-compatible. I used the parallel port for simplicity; there may be an I2C serial port solution somewhere as well.

My daughter took the pictures, I really don't know anything about taking "focused pictures". All I did was resize them and resample to 72 dpi. That information would be nice to have.

What I would really want is for someone like GameCab to make a PCB out of this circuit and give me the first one free. It would be easy to put in a way to control 20 more LEDs if necessary.

I haven't looked at the GP-Wiz49 since it is USB. 







Trimoor:
Is the LED driver a MAXIM chip?  I tried one once, but I couldn't get the parallel interface to work properly.  The only problem is they cost over 5 bucks apiece, which is a ripoff for what little they do.  I guess you could sell it with just a chip socket and have everyone order their own free 'samples'.

Buddabing:

--- Quote from: Trimoor on April 10, 2005, 08:12:58 pm ---Is the LED driver a MAXIM chip?  I tried one once, but I couldn't get the parallel interface to work properly.  The only problem is they cost over 5 bucks apiece, which is a ripoff for what little they do.  I guess you could sell it with just a chip socket and have everyone order their own free 'samples'.

--- End quote ---

Yep, MAX6956ANI. They cost something like $5.31 each plus shipping in quantity of 1, but they give discounts for 25 or more ordered.  ($4.28)  I tried ordering some samples, but they never arrived.

Most of the circuit is in the parallel interface, the LED controller part is just one IC, a .1 uf cap, and a resistor. It was well worth the $5.31 to me to save the trouble. I can get the fade effects, too, and most of the low-level programming was done for me already in the application notes.

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